A visual control for a media-related command. It can be used anywhere the user can interact with active media.
Examples of controls:
Toggle play/pause state.
Play media ID "x".
Remove favorite state from media item "y".
The type of the control, which is used by TtButton to apply one of the predefined styles. May be overridden in subclasses in order to apply a specialized style. TtButton.ActionType.TERTIARY is used by default as the most neutral option.